Never stop, never give up.

That's the advice offered to first aid trainees learning how to administer CPR in the hope that, one day, they'll be able to help someone in need.

Bryan Wong of Pacific First Aid says the amazing story of Christine Newman - a lost snowshoer who survived severe hypothermia after receiving CPR for four hours - is proof positive that tireless rescue efforts pay off.

Wong says it's a false myth that CPR, or cardiopulmonary resuscitation, should be abandoned after an hour at the most.

"Ideally, when you do CPR you don't stop at all," Wong said."You continue until you're too tired to go on, or you can stop to apply an AED [automated external defibrillator], or other responders or paramedics arrive."

Newman was found on B.C.'s Mount Garibaldi last week, severely hypothermic and in cardiac arrest, having spent several hours outdoors, trapped in a tree well in deep snow up to her neck.

Christine 'Tink' Newman

Snowshoer Christine 'Tink' Newman survived hypothermia and cardiac arrest after a group of strangers spent four hours giving her CPR. (Facebook)

She's now recovering in hospital, alive thanks to fellow snowshoers, who tirelessly administered CPR for four hours.

"If a person is not getting up and saying 'Get off my chest', continue on because you're getting their heart to move," advises Wong.

He says the best thing anyone can do to help someone in cardiac arrest is get first aid training, but failing that, just start chest compressions.

The Heart and Stroke Foundation has helped author the Guidelines for CPR, directing that compressions be administered hard and quickly, about 100 times a minute.

"Compressions are better than doing nothing at all," said Wong.

Performing CPR and using an AED before emergency responders arrive can increase a person's chance of surviving cardiac arrest by up to 75 per cent.

CPR courses are available through Pacific First Aid, St.John Ambulance and other agencies.

A CPR Anytime Kit is available through the Heart and Stroke Foundation, which has partnered with the City of Vancouver to install AEDs in public spaces throughout the community.

On mobile? Click here to see an interactive slider about CPR techniques

Do you have CPR training? Do you have an amazing story of survival? Tell us in the comments below.

With files from the CBC's Meera Bains